Metallized rare earth garnet and metal seals to same

Abstract

A reliable garnet to metal hermetic seal is obtained by metallizing the garnet with successive sputtered layers of tantalum or titanium, molybdenum or tungsten and nickel, followed by soldering or brazing the metallized garnet to a metal member.

We claim: 
     
       1. A metallized garnet comprising a body of garnet having a surface to be bonded, a first layer of a reactive metal sputter deposited on at least a portion of the garnet surface, a second layer of a refractory metal sputter deposited on the first layer, and a third layer of a solderable metal sputter deposited on the second layer. 
     
     
       2. The metallized garnet of claim 1 in which the reactive metal is selected from the group consisting of tantalum, titanium, vanadium, hafnium, zirconium, niobium and alloys thereof. 
     
     
       3. The metallized garnet of claim 1 in which the refractory metal is selected from the group consisting of molybdenum and tungsten. 
     
     
       4. The metallized garnet of claim 1 in which the solderable metal is nickel. 
     
     
       5. The metallized garnet of claim 1 in which the reactive metal is selected from the group consisting of tantalum and titanium, the refractory metal is molybdenum and the solderable metal is nickel. 
     
     
       6. The metallized garnet of claim 5 in which the first layer is about one-half micron in thickness and the second and third layers are each about one micron in thickness.